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| Author(s): |
Julio Barboza Chiquetto
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Filosofia, Letras e Ciências Humanas (FFLCH/SBD) |
| Defense date: | 2016-08-26 |
| Examining board members: |
Maria Elisa Siqueira Silva;
Débora Souza Alvim;
Margarete Cristiane de Costa Trindade Amorim;
Flávia Noronha Dutra Ribeiro;
Rita Yuri Ynoue
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| Advisor: | Maria Elisa Siqueira Silva |
| Abstract | |
High concentrations of pollutants such as tropospheric ozone pose health risks for the population of the São Paulo Metropolitan Area (SPMA). It is influenced by complex factors from anthropogenic (emission of precursor pollutants) and natural (such as the availability of sunlight) origin, typical of the study region. In the first part of the study, state Environmental Agency (CETESB) monitoring stations were classified per their land use, using WHO criteria, into vehicular, commercial, residential and urban background. Also, pollutant time series from 1996-2011 from these stations were analysed, mainly through the comparison of the ozone seasonal cycle in monitoring stations with different land use classes. The second part of the study was focused on the evaluation in the atmospheric model WRF/Chem 3.2.1, of sensitivity tests, where changes on the emission and land use characteristics were performed in GIS softwares, configuring different scenarios which were compared to a control simulation during a period of intense availability of sunlight in the study region. Results from the first part indicated that higher average ozone concentrations were found in stations with residential and urban background land use classes (with the highest monthly average of 57 gm-3 or 28 ppb in October at Pico do Jaraguá station), and lower in vehicular and commercial stations (with the lowest monthly average of 6 gm-3 or 3 ppb in June at Lapa station), the opposite of what was found for other pollutants, both in the diurnal and seasonal scales. Significant correlations were calculated between stations with similar land use classes. Results from the second part (atmospheric modelling) showed that the size of the altered area strongly impacts the intensity and spatial distribution of the changes simulated for ozone and other primary pollutants evaluated. The scenarios with more intense emission decrease (100%) also indicated more intense changes compared to the scenarios with moderated decrease (50%). Scenarios with decreased total vehicle number also presented significant reduction in ozone, with an average decrease of 18 gm-3 or 9 ppb during the day in a scenario simulating an urban toll in downtown São Paulo. The local sea breeze circulation determined the transport of the excess or deficit of ozone and other precursor pollutants to different regions within the SPMA. Changes in land use induced different atmospheric circulation characteristics by changing the surface thermodynamic properties and by the emission of biogenic compounds which act as precursors for ozone, resulting in higher concentrations within the modified areas (with an increase of 10 gm-3 or 5 ppb during all hours of the day in the scenario which simulates the building of an urban park in Sao Paulo) and transport for more distant areas. As a conclusion, the building of a park within the current infrastructure and environmental conditions in the SPMA should increase average ozone concentrations in the modified areas (with possible impacts of increase and reduction in near and far regions, according to the prevailing atmospheric circulation), specially if it is located relatively near avenues with intense vehicle circulation. We suggest focus on public and non-motorized transport systems, proper land use management and policies for the development of cleaner fuels for the mitigation of these problems and implementation of urban parks without increasing ozone concentrations. (AU) | |
| FAPESP's process: | 12/12216-5 - Spatial distribution of tropospheric ozone associated with the land use in the Sao Paulo Metropolitan Region |
| Grantee: | Júlio Barboza Chiquetto |
| Support Opportunities: | Scholarships in Brazil - Doctorate |